package fetcher

import (
	"errors"
	"math/big"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/stateless"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/eth/protocols/eth"
	"github.com/ethereum/go-ethereum/eth/protocols/wit"
	"github.com/ethereum/go-ethereum/rlp"
	"github.com/ethereum/go-ethereum/trie"
)

// Test helper functions
func createTestBlock(number uint64) *types.Block {
	header := &types.Header{
		Number: big.NewInt(int64(number)),
	}
	return types.NewBlock(header, nil, nil, trie.NewStackTrie(nil))
}

func createTestWitnessForBlock(block *types.Block) *stateless.Witness {
	witness, err := stateless.NewWitness(block.Header(), nil)
	if err != nil {
		panic(err)
	}
	return witness
}

func createTestBlockAnnounce(origin string, block *types.Block, fetchWitness witnessRequesterFn) *blockAnnounce {
	return &blockAnnounce{
		origin:       origin,
		hash:         block.Hash(),
		number:       block.NumberU64(),
		time:         time.Now(),
		fetchWitness: fetchWitness,
	}
}

// Test setup helper
type testWitnessManager struct {
	manager      *witnessManager
	quit         chan struct{}
	enqueueCh    chan *enqueueRequest
	droppedPeers []string
	mu           sync.Mutex
}

func newTestWitnessManager() *testWitnessManager {
	quit := make(chan struct{})
	enqueueCh := make(chan *enqueueRequest, 10)

	tw := &testWitnessManager{
		quit:      quit,
		enqueueCh: enqueueCh,
	}

	dropPeer := peerDropFn(func(id string) {
		tw.mu.Lock()
		tw.droppedPeers = append(tw.droppedPeers, id)
		tw.mu.Unlock()
	})

	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	tw.manager = newWitnessManager(quit, dropPeer, enqueueCh, getBlock, getHeader, chainHeight)
	return tw
}

func (tw *testWitnessManager) Close() {
	close(tw.quit)
}

func (tw *testWitnessManager) DroppedPeers() []string {
	tw.mu.Lock()
	defer tw.mu.Unlock()
	result := make([]string, len(tw.droppedPeers))
	copy(result, tw.droppedPeers)
	return result
}

func (tw *testWitnessManager) PendingCount() int {
	tw.manager.mu.Lock()
	defer tw.manager.mu.Unlock()
	return len(tw.manager.pending)
}

// TestWitnessManagerCreation tests the creation and basic setup of witnessManager
func TestWitnessManagerCreation(t *testing.T) {
	tw := newTestWitnessManager()
	defer tw.Close()

	if tw.manager == nil {
		t.Fatal("Expected witnessManager to be created")
	}

	// Check initial state
	if tw.PendingCount() != 0 {
		t.Errorf("Expected empty pending map, got %d items", tw.PendingCount())
	}

	if tw.manager.witnessTimer == nil {
		t.Error("Expected witnessTimer to be initialized")
	}

	// Test channels are created with proper buffering
	if cap(tw.manager.injectNeedWitnessCh) != 10 {
		t.Errorf("Expected injectNeedWitnessCh buffer size 10, got %d", cap(tw.manager.injectNeedWitnessCh))
	}

	if cap(tw.manager.injectWitnessCh) != 10 {
		t.Errorf("Expected injectWitnessCh buffer size 10, got %d", cap(tw.manager.injectWitnessCh))
	}
}

// TestWitnessManagerLifecycle tests start and stop functionality
func TestWitnessManagerLifecycle(t *testing.T) {
	tw := newTestWitnessManager()
	defer tw.Close()

	// Start the manager
	tw.manager.start()

	// Give it a moment to start
	time.Sleep(10 * time.Millisecond)

	// Stop the manager
	tw.manager.stop()

	// Give it a moment to stop
	time.Sleep(10 * time.Millisecond)
}

// TestHandleNeed tests processing of blocks needing witnesses
func TestHandleNeed(t *testing.T) {
	tw := newTestWitnessManager()
	defer tw.Close()

	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	msg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: fetchWitness,
	}

	// Test successful handling
	tw.manager.handleNeed(msg)

	// Check that block was added to pending
	if !tw.manager.isPending(block.Hash()) {
		t.Error("Expected block to be pending after handleNeed")
	}

	// Check pending count
	if tw.PendingCount() != 1 {
		t.Errorf("Expected 1 pending request, got %d", tw.PendingCount())
	}
}

// TestHandleNeedDuplicates tests that duplicate requests are handled properly
func TestHandleNeedDuplicates(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	msg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: fetchWitness,
	}

	// First request should succeed
	manager.handleNeed(msg)

	// Second request should be ignored
	manager.handleNeed(msg)

	// Check pending count is still 1
	manager.mu.Lock()
	pendingCount := len(manager.pending)
	manager.mu.Unlock()

	if pendingCount != 1 {
		t.Errorf("Expected 1 pending request after duplicate, got %d", pendingCount)
	}
}

// TestHandleNeedKnownBlock tests handling of blocks already known locally
func TestHandleNeedKnownBlock(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	block := createTestBlock(101)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block {
		if hash == block.Hash() {
			return block
		}
		return nil
	})
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	msg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: fetchWitness,
	}

	// Should be ignored since block is known
	manager.handleNeed(msg)

	// Check that no pending requests were created
	manager.mu.Lock()
	pendingCount := len(manager.pending)
	manager.mu.Unlock()

	if pendingCount != 0 {
		t.Errorf("Expected 0 pending requests for known block, got %d", pendingCount)
	}
}

// TestHandleBroadcast tests processing of injected witnesses
func TestHandleBroadcast(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	var enqueueRequests []*enqueueRequest
	var enqueueMutex sync.Mutex

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Start a goroutine to collect enqueue requests
	go func() {
		for req := range enqueueCh {
			enqueueMutex.Lock()
			enqueueRequests = append(enqueueRequests, req)
			enqueueMutex.Unlock()
		}
	}()

	block := createTestBlock(101)
	witness := createTestWitnessForBlock(block)

	// First add a pending request
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	needMsg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: fetchWitness,
	}
	manager.handleNeed(needMsg)

	// Now inject the witness
	witnessMsg := &injectedWitnessMsg{
		peer:    "broadcast-peer",
		witness: witness,
		time:    time.Now(),
	}
	manager.handleBroadcast(witnessMsg)

	// Give time for async processing
	time.Sleep(50 * time.Millisecond)

	// Check that request was enqueued
	enqueueMutex.Lock()
	reqCount := len(enqueueRequests)
	enqueueMutex.Unlock()

	if reqCount != 1 {
		t.Errorf("Expected 1 enqueue request, got %d", reqCount)
	}

	// Check that pending state was cleaned up
	if manager.isPending(block.Hash()) {
		t.Error("Expected block to no longer be pending after witness broadcast")
	}
}

// TestWitnessUnavailable tests witness unavailability tracking
func TestWitnessUnavailable(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	hash := common.HexToHash("0x123")

	// Initially should not be unavailable
	if manager.isWitnessUnavailable(hash) {
		t.Error("Expected witness to not be unavailable initially")
	}

	// Mark as unavailable
	manager.markWitnessUnavailable(hash)

	// Should now be unavailable
	if !manager.isWitnessUnavailable(hash) {
		t.Error("Expected witness to be unavailable after marking")
	}

	// Wait for expiry (using a short timeout for testing)
	originalTimeout := witnessUnavailableTimeout
	// We can't modify the const, so we'll test cleanup instead
	manager.cleanupUnavailableCache()

	// Should still be unavailable (hasn't expired yet)
	if !manager.isWitnessUnavailable(hash) {
		t.Error("Expected witness to still be unavailable before timeout")
	}

	// Manually expire the entry for testing
	manager.mu.Lock()
	manager.witnessUnavailable[hash] = time.Now().Add(-time.Minute)
	manager.mu.Unlock()

	// Should now be available again
	if manager.isWitnessUnavailable(hash) {
		t.Error("Expected witness to be available after expiry")
	}

	// Restore original timeout
	_ = originalTimeout
}

// TestForget tests cleanup of pending state
func TestForget(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	msg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: fetchWitness,
	}

	// Add pending request
	manager.handleNeed(msg)

	// Verify it's pending
	if !manager.isPending(block.Hash()) {
		t.Error("Expected block to be pending before forget")
	}

	// Forget the block
	manager.forget(block.Hash())

	// Verify it's no longer pending
	if manager.isPending(block.Hash()) {
		t.Error("Expected block to not be pending after forget")
	}
}

// TestHandleFilterResult tests integration with BlockFetcher's filter results
func TestHandleFilterResult(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := createTestBlockAnnounce("test-peer", block, fetchWitness)

	// Handle filter result
	manager.handleFilterResult(announce, block)

	// Check that block was added to pending
	if !manager.isPending(block.Hash()) {
		t.Error("Expected block to be pending after handleFilterResult")
	}
}

// TestCheckCompleting tests the checkCompleting functionality
func TestCheckCompleting(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := createTestBlockAnnounce("test-peer", block, fetchWitness)

	// Check completing
	manager.checkCompleting(announce, block)

	// Check that block was added to pending
	if !manager.isPending(block.Hash()) {
		t.Error("Expected block to be pending after checkCompleting")
	}
}

// TestWitnessFetchFailure tests handling of witness fetch failures
func TestWitnessFetchFailure(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	droppedPeer := ""

	dropPeer := peerDropFn(func(id string) {
		droppedPeer = id
	})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	hash := common.HexToHash("0x123")
	peer := "test-peer"
	err := errors.New("fetch failed")

	// Test soft failure (keep pending for retry) - peer should still be dropped
	manager.handleWitnessFetchFailureExt(hash, peer, err, false)

	if droppedPeer != peer {
		t.Errorf("Expected peer to be dropped on soft failure, got %s", droppedPeer)
	}
}

// TestWitnessFetchFailureAlwaysDropsPeer tests that handleWitnessFetchFailureExt
// always drops the peer regardless of removePending flag
func TestWitnessFetchFailureAlwaysDropsPeer(t *testing.T) {
	tw := newTestWitnessManager()
	defer tw.Close()

	hash := common.HexToHash("0x123")
	peer1 := "test-peer-1"
	peer2 := "test-peer-2"
	err := errors.New("fetch failed")

	// Add a pending request to test removal behavior
	block := createTestBlock(101)
	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin: peer1,
			block:  block,
		},
		announce: &blockAnnounce{
			origin: peer1,
			hash:   hash,
			number: 101,
			time:   time.Now(),
			fetchWitness: func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
				return nil, nil
			},
		},
		retries: 0,
	}

	tw.manager.mu.Lock()
	tw.manager.pending[hash] = state
	tw.manager.mu.Unlock()

	// Test soft failure (removePending = false) - peer should be dropped
	tw.manager.handleWitnessFetchFailureExt(hash, peer1, err, false)

	droppedPeers := tw.DroppedPeers()
	if len(droppedPeers) != 1 || droppedPeers[0] != peer1 {
		t.Errorf("Expected peer1 to be dropped on soft failure, got %v", droppedPeers)
	}

	// Verify pending request was NOT removed (soft failure)
	if !tw.manager.isPending(hash) {
		t.Error("Expected pending request to remain after soft failure")
	}

	// Test hard failure (removePending = true) - peer should also be dropped
	tw.manager.handleWitnessFetchFailureExt(hash, peer2, err, true)

	droppedPeers = tw.DroppedPeers()
	if len(droppedPeers) != 2 || droppedPeers[1] != peer2 {
		t.Errorf("Expected peer2 to be dropped on hard failure, got %v", droppedPeers)
	}

	// Verify pending request was removed (hard failure)
	if tw.manager.isPending(hash) {
		t.Error("Expected pending request to be removed after hard failure")
	}
}

// TestWitnessFetchFailureEmptyPeer tests that no peer is dropped when peer string is empty
func TestWitnessFetchFailureEmptyPeer(t *testing.T) {
	tw := newTestWitnessManager()
	defer tw.Close()

	hash := common.HexToHash("0x123")
	err := errors.New("fetch failed")

	// Test with empty peer string - no peer should be dropped
	tw.manager.handleWitnessFetchFailureExt(hash, "", err, false)

	droppedPeers := tw.DroppedPeers()
	if len(droppedPeers) != 0 {
		t.Errorf("Expected no peer to be dropped when peer string is empty, got %v", droppedPeers)
	}
}

// TestCleanupUnavailableCache tests the cleanup of expired unavailable entries
func TestCleanupUnavailableCache(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	hash1 := common.HexToHash("0x123")
	hash2 := common.HexToHash("0x456")

	// Add entries with different expiry times
	manager.mu.Lock()
	manager.witnessUnavailable[hash1] = time.Now().Add(-time.Hour) // Expired
	manager.witnessUnavailable[hash2] = time.Now().Add(time.Hour)  // Not expired
	manager.mu.Unlock()

	// Run cleanup
	manager.cleanupUnavailableCache()

	// Check results
	manager.mu.Lock()
	_, hash1Exists := manager.witnessUnavailable[hash1]
	_, hash2Exists := manager.witnessUnavailable[hash2]
	cacheSize := len(manager.witnessUnavailable)
	manager.mu.Unlock()

	if hash1Exists {
		t.Error("Expected expired hash1 to be cleaned up")
	}

	if !hash2Exists {
		t.Error("Expected non-expired hash2 to remain")
	}

	if cacheSize != 1 {
		t.Errorf("Expected cache size 1 after cleanup, got %d", cacheSize)
	}
}

// TestWitnessFetchWithBlockNoLongerPending tests the new error handling when a block
// is removed from pending during witness fetch
func TestWitnessFetchWithBlockNoLongerPending(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	blockHash := block.Hash()
	witness := createTestWitnessForBlock(block)

	// Create a channel to control witness fetch timing
	fetchStarted := make(chan struct{})
	var responseSent atomic.Bool

	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		// Signal that fetch has started
		close(fetchStarted)

		// Send the response in a goroutine
		go func() {
			// Wait a bit to ensure we're in the middle of processing
			time.Sleep(10 * time.Millisecond)

			// Before sending response, remove block from pending
			manager.mu.Lock()
			delete(manager.pending, blockHash)
			manager.mu.Unlock()

			// Now send the response with the correct structure
			witnessBytes, _ := rlp.EncodeToBytes(witness)
			responseCh <- &eth.Response{
				Res: &wit.WitnessPacketRLPPacket{
					WitnessPacketResponse: wit.WitnessPacketResponse{{Data: rlp.RawValue(witnessBytes)}},
				},
				Done: make(chan error, 1),
			}
			responseSent.Store(true)
		}()

		// Return successful request
		req := &eth.Request{
			Peer: "test-peer",
			Sent: time.Now(),
		}
		return req, nil
	}

	// Create message to inject block that needs witness
	msg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		time:         time.Now(),
		fetchWitness: fetchWitness,
	}

	// Inject the block
	manager.handleNeed(msg)

	// Verify block is pending
	manager.mu.Lock()
	if _, exists := manager.pending[blockHash]; !exists {
		t.Fatal("Block should be pending after handleNeed")
	}
	manager.mu.Unlock()

	// Trigger tick to start witness fetch
	manager.tick()

	// Wait for fetch to start
	<-fetchStarted

	// Give time for the response to be processed
	time.Sleep(50 * time.Millisecond)

	// Verify response was sent and block is no longer pending
	if !responseSent.Load() {
		t.Error("Response should have been sent")
	}

	manager.mu.Lock()
	_, exists := manager.pending[blockHash]
	manager.mu.Unlock()

	if exists {
		t.Error("Block should not be pending after being removed during fetch")
	}

	// Check that no enqueue occurred (since block was removed from pending)
	select {
	case <-enqueueCh:
		t.Error("Should not enqueue block that was removed from pending")
	default:
		// Expected - no enqueue
	}
}

// TestTick tests the witness timer tick functionality
func TestTick(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Test tick with no pending requests
	manager.tick()

	// Add a pending request but make it NOT ready to fetch to avoid goroutine issues
	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := &blockAnnounce{
		origin:       "test-peer",
		hash:         block.Hash(),
		number:       block.NumberU64(),
		time:         time.Now().Add(time.Hour), // Future time - not ready to fetch yet
		fetchWitness: fetchWitness,
	}

	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin: "test-peer",
			block:  block,
		},
		announce: announce,
		retries:  0,
	}

	manager.mu.Lock()
	manager.pending[block.Hash()] = state
	manager.mu.Unlock()

	// Test tick with pending request NOT ready to fetch
	manager.tick()

	// Verify retry count didn't increase (request wasn't processed)
	manager.mu.Lock()
	retries := state.retries
	manager.mu.Unlock()

	if retries != 0 {
		t.Errorf("Expected retry count to remain 0 for not-ready request, got %d", retries)
	}

	// Now test with a ready request but handle it manually to avoid goroutine
	// Set the announce time to past
	announce.time = time.Now().Add(-time.Second) // Ready to fetch

	// Manual test of the retry increment logic (what tick would do)
	manager.mu.Lock()
	if time.Now().After(announce.time) && state.retries < maxWitnessFetchRetries {
		state.retries++ // This is what tick() would do
	}
	manager.mu.Unlock()

	// Verify retry count increased
	manager.mu.Lock()
	retries = state.retries
	manager.mu.Unlock()

	if retries != 1 {
		t.Errorf("Expected retry count 1 after manual increment, got %d", retries)
	}
}

// TestTickMaxRetries tests that tick gives up after max retries
func TestTickMaxRetries(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	announce := &blockAnnounce{
		origin: "test-peer",
		hash:   block.Hash(),
		number: block.NumberU64(),
		time:   time.Now().Add(-time.Second), // Ready to fetch
		fetchWitness: func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
			return nil, nil
		},
	}

	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin: "test-peer",
			block:  block,
		},
		announce: announce,
		retries:  maxWitnessFetchRetries, // Already at max retries
	}

	manager.mu.Lock()
	manager.pending[block.Hash()] = state
	manager.mu.Unlock()

	// Test tick should mark witness as unavailable
	manager.tick()

	// Verify witness marked as unavailable
	if !manager.isWitnessUnavailable(block.Hash()) {
		t.Error("Expected witness to be marked unavailable after max retries")
	}
}

// TestTickWithWitnessAlreadyPresent tests tick with witness already attached
func TestTickWithWitnessAlreadyPresent(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	var enqueueRequests []*enqueueRequest
	var enqueueMutex sync.Mutex

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Start goroutine to collect enqueue requests
	go func() {
		for req := range enqueueCh {
			enqueueMutex.Lock()
			enqueueRequests = append(enqueueRequests, req)
			enqueueMutex.Unlock()
		}
	}()

	block := createTestBlock(101)
	witness := createTestWitnessForBlock(block)

	announce := &blockAnnounce{
		origin: "test-peer",
		hash:   block.Hash(),
		number: block.NumberU64(),
		time:   time.Now().Add(-time.Second), // Ready to fetch (this will be updated)
		fetchWitness: func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
			return nil, nil
		},
	}

	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin:  "test-peer",
			block:   block,
			witness: witness, // Witness already present
		},
		announce: announce,
		retries:  0,
	}

	manager.mu.Lock()
	manager.pending[block.Hash()] = state
	manager.mu.Unlock()

	// Directly test that safeEnqueue is called for blocks with witnesses
	// Instead of calling tick (which triggers fetchWitness), directly call safeEnqueue
	manager.safeEnqueue(state.op)

	time.Sleep(10 * time.Millisecond) // Give time for async processing

	// Verify block was enqueued
	enqueueMutex.Lock()
	reqCount := len(enqueueRequests)
	enqueueMutex.Unlock()

	if reqCount != 1 {
		t.Errorf("Expected 1 enqueue request, got %d", reqCount)
	}

	// Verify pending state was cleaned up
	if manager.isPending(block.Hash()) {
		t.Error("Expected pending state to be cleaned up after enqueue")
	}
}

// TestHandleWitnessFetchSuccess tests successful witness fetch handling
func TestHandleWitnessFetchSuccess(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	var enqueueRequests []*enqueueRequest
	var enqueueMutex sync.Mutex

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Start goroutine to collect enqueue requests
	go func() {
		for req := range enqueueCh {
			enqueueMutex.Lock()
			enqueueRequests = append(enqueueRequests, req)
			enqueueMutex.Unlock()
		}
	}()

	block := createTestBlock(101)
	witness := createTestWitnessForBlock(block)

	// Add pending state
	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin: "test-peer",
			block:  block,
		},
	}

	manager.mu.Lock()
	manager.pending[block.Hash()] = state
	manager.mu.Unlock()

	// Test successful witness fetch
	announcedAt := time.Now()
	manager.handleWitnessFetchSuccess("fetch-peer", block.Hash(), witness, announcedAt)

	time.Sleep(10 * time.Millisecond) // Give time for async processing

	// Verify witness was attached and block enqueued
	enqueueMutex.Lock()
	reqCount := len(enqueueRequests)
	enqueueMutex.Unlock()

	if reqCount != 1 {
		t.Errorf("Expected 1 enqueue request, got %d", reqCount)
	}

	// Verify witness is attached
	if state.op.witness == nil {
		t.Error("Expected witness to be attached to operation")
	}
}

// TestHandleWitnessFetchSuccessNoPending tests success handler with no pending block
func TestHandleWitnessFetchSuccessNoPending(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	witness := createTestWitnessForBlock(block)

	// Test with no pending state - should handle gracefully
	announcedAt := time.Now()
	manager.handleWitnessFetchSuccess("fetch-peer", block.Hash(), witness, announcedAt)

	// Should not panic or cause issues
}

// TestHandleWitnessFetchSuccessWitnessAlreadyPresent tests success with witness already present
func TestHandleWitnessFetchSuccessWitnessAlreadyPresent(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	witness1 := createTestWitnessForBlock(block)
	witness2 := createTestWitnessForBlock(block)

	// Add pending state with witness already present
	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin:  "test-peer",
			block:   block,
			witness: witness1, // Already has witness
		},
	}

	manager.mu.Lock()
	manager.pending[block.Hash()] = state
	manager.mu.Unlock()

	// Test with witness already present - should be ignored
	announcedAt := time.Now()
	manager.handleWitnessFetchSuccess("fetch-peer", block.Hash(), witness2, announcedAt)

	// Verify original witness is still there
	if state.op.witness != witness1 {
		t.Error("Expected original witness to remain unchanged")
	}
}

// TestRescheduleWitness tests the witness timer rescheduling logic
func TestRescheduleWitness(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Test with no pending items - timer should be stopped
	manager.rescheduleWitness()

	// Add a pending item
	block := createTestBlock(101)
	announce := &blockAnnounce{
		origin: "test-peer",
		hash:   block.Hash(),
		number: block.NumberU64(),
		time:   time.Now().Add(time.Second), // Future time
		fetchWitness: func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
			return nil, nil
		},
	}

	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin: "test-peer",
			block:  block,
		},
		announce: announce,
	}

	manager.mu.Lock()
	manager.pending[block.Hash()] = state
	manager.mu.Unlock()

	// Test with pending item - timer should be scheduled
	manager.rescheduleWitness()

	// Verify timer is active (we can't directly check, but it shouldn't panic)
}

// TestSafeEnqueueWithNilWitness tests safeEnqueue error handling
func TestSafeEnqueueWithNilWitness(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	op := &blockOrHeaderInject{
		origin:  "test-peer",
		block:   block,
		witness: nil, // Nil witness should cause error handling
	}

	// Add to pending first
	manager.mu.Lock()
	manager.pending[block.Hash()] = &witnessRequestState{op: op}
	manager.mu.Unlock()

	// Test safeEnqueue with nil witness
	manager.safeEnqueue(op)

	// Verify pending state was cleaned up
	if manager.isPending(block.Hash()) {
		t.Error("Expected pending state to be cleaned up after nil witness error")
	}
}

// TestSafeEnqueueChannelClosed tests safeEnqueue when parent channel is closed
func TestSafeEnqueueChannelClosed(t *testing.T) {
	quit := make(chan struct{})
	close(quit) // Close quit channel to simulate shutdown

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10) // Don't close this - let quit handle shutdown
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	witness := createTestWitnessForBlock(block)
	op := &blockOrHeaderInject{
		origin:  "test-peer",
		block:   block,
		witness: witness,
	}

	// Test safeEnqueue with closed quit channel - should handle gracefully via quit path
	manager.safeEnqueue(op)

	// Should not panic and should use the quit channel path
}

// TestHandleNeedDistanceCheck tests handleNeed with distance check
func TestHandleNeedDistanceCheck(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 }) // Chain at height 100

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Create block that's too far away (block 10 when chain is at 100)
	block := createTestBlock(10)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	msg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: fetchWitness,
	}

	// Test handleNeed with distant block - should be discarded
	manager.handleNeed(msg)

	// Check that no pending requests were created
	if manager.isPending(block.Hash()) {
		t.Error("Expected distant block to be discarded")
	}
}

// TestHandleNeedMissingFetchWitness tests handleNeed with nil fetchWitness
func TestHandleNeedMissingFetchWitness(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)

	msg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: nil, // Missing fetchWitness function
	}

	// Test handleNeed with nil fetchWitness - should be handled gracefully
	manager.handleNeed(msg)

	// Check that no pending requests were created
	if manager.isPending(block.Hash()) {
		t.Error("Expected request without fetchWitness to be ignored")
	}
}

// TestLoop tests the main event loop with different message types
func TestLoop(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Start the loop
	go manager.loop()

	// Test injecting a block need witness message
	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	needMsg := &injectBlockNeedWitnessMsg{
		origin:       "test-peer",
		block:        block,
		fetchWitness: fetchWitness,
	}

	// Send message through channel
	select {
	case manager.injectNeedWitnessCh <- needMsg:
	case <-time.After(100 * time.Millisecond):
		t.Fatal("Failed to send need witness message")
	}

	// Give time for processing
	time.Sleep(50 * time.Millisecond)

	// Verify block is pending
	if !manager.isPending(block.Hash()) {
		t.Error("Expected block to be pending after loop processing")
	}

	// Test injecting a witness message
	witness := createTestWitnessForBlock(block)
	witnessMsg := &injectedWitnessMsg{
		peer:    "broadcast-peer",
		witness: witness,
		time:    time.Now(),
	}

	// Send witness message through channel
	select {
	case manager.injectWitnessCh <- witnessMsg:
	case <-time.After(100 * time.Millisecond):
		t.Fatal("Failed to send witness message")
	}

	// Give time for processing
	time.Sleep(50 * time.Millisecond)

	// The loop should terminate when quit channel is closed
}

// TestHandleFilterResultWithoutWitness tests handleFilterResult when witness not needed
func TestHandleFilterResultWithoutWitness(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	announce := &blockAnnounce{
		origin:       "test-peer",
		hash:         block.Hash(),
		number:       block.NumberU64(),
		time:         time.Now(),
		fetchWitness: nil, // No witness needed
	}

	// Handle filter result without witness requirement
	manager.handleFilterResult(announce, block)

	// Check that block was NOT added to pending
	if manager.isPending(block.Hash()) {
		t.Error("Expected block without witness requirement to not be pending")
	}
}

// TestCheckCompletingWithoutWitness tests checkCompleting when witness not needed
func TestCheckCompletingWithoutWitness(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	announce := &blockAnnounce{
		origin:       "test-peer",
		hash:         block.Hash(),
		number:       block.NumberU64(),
		time:         time.Now(),
		fetchWitness: nil, // No witness needed
	}

	// Check completing without witness requirement
	manager.checkCompleting(announce, block)

	// Check that block was NOT added to pending
	if manager.isPending(block.Hash()) {
		t.Error("Expected block without witness requirement to not be pending")
	}
}

// TestFetchWitnessError tests fetchWitness error handling
func TestFetchWitnessError(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	hash := common.HexToHash("0x123")
	peer := "test-peer"

	// Test fetchWitness with error in initiating request
	announce := &blockAnnounce{
		origin: peer,
		hash:   hash,
		number: 101,
		time:   time.Now(),
		fetchWitness: func(common.Hash, chan *eth.Response) (*eth.Request, error) {
			return nil, errors.New("no peer available")
		},
	}

	// This will run in background, we can't easily wait for it, but it exercises the error path
	go manager.fetchWitness(peer, hash, announce)

	time.Sleep(50 * time.Millisecond) // Give time for goroutine to process
}

// TestHandleFilterResultWitnessUnavailable tests filter result with unavailable witness
func TestHandleFilterResultWitnessUnavailable(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)

	// Mark witness as unavailable first
	manager.markWitnessUnavailable(block.Hash())

	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := createTestBlockAnnounce("test-peer", block, fetchWitness)

	// Handle filter result with unavailable witness
	manager.handleFilterResult(announce, block)

	// Check that block was NOT added to pending
	if manager.isPending(block.Hash()) {
		t.Error("Expected block with unavailable witness to be discarded")
	}
}

// TestHandleFilterResultDuplicate tests filter result with already pending block
func TestHandleFilterResultDuplicate(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := createTestBlockAnnounce("test-peer", block, fetchWitness)

	// Add to pending first
	manager.handleFilterResult(announce, block)

	// Try to handle the same filter result again
	manager.handleFilterResult(announce, block)

	// Should still only have one pending request
	manager.mu.Lock()
	pendingCount := len(manager.pending)
	manager.mu.Unlock()

	if pendingCount != 1 {
		t.Errorf("Expected 1 pending request after duplicate filter result, got %d", pendingCount)
	}
}

// TestCheckCompletingWitnessUnavailable tests checkCompleting with unavailable witness
func TestCheckCompletingWitnessUnavailable(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)

	// Mark witness as unavailable first
	manager.markWitnessUnavailable(block.Hash())

	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := createTestBlockAnnounce("test-peer", block, fetchWitness)

	// Check completing with unavailable witness
	manager.checkCompleting(announce, block)

	// Check that block was NOT added to pending
	if manager.isPending(block.Hash()) {
		t.Error("Expected block with unavailable witness to be discarded")
	}
}

// TestCheckCompletingDuplicate tests checkCompleting with already pending block
func TestCheckCompletingDuplicate(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := createTestBlockAnnounce("test-peer", block, fetchWitness)

	// Add to pending first
	manager.checkCompleting(announce, block)

	// Try to check completing the same block again
	manager.checkCompleting(announce, block)

	// Should still only have one pending request
	manager.mu.Lock()
	pendingCount := len(manager.pending)
	manager.mu.Unlock()

	if pendingCount != 1 {
		t.Errorf("Expected 1 pending request after duplicate checkCompleting, got %d", pendingCount)
	}
}

// TestCheckCompletingKnownBlock tests checkCompleting with already known block
func TestCheckCompletingKnownBlock(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	block := createTestBlock(101)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block {
		if hash == block.Hash() {
			return block
		}
		return nil
	})
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	fetchWitness := func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
		return nil, nil
	}

	announce := createTestBlockAnnounce("test-peer", block, fetchWitness)

	// Check completing with known block
	manager.checkCompleting(announce, block)

	// Check that block was NOT added to pending
	if manager.isPending(block.Hash()) {
		t.Error("Expected known block to be ignored")
	}
}

// TestTickInvalidPendingState tests tick with invalid pending state
func TestTickInvalidPendingState(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	hash := common.HexToHash("0x123")

	// Add invalid pending state (missing op or announce)
	manager.mu.Lock()
	manager.pending[hash] = &witnessRequestState{
		op:       nil, // Invalid - nil op
		announce: nil, // Invalid - nil announce
		retries:  0,
	}
	manager.mu.Unlock()

	// Test tick should clean up invalid state
	manager.tick()

	// Verify invalid state was cleaned up
	if manager.isPending(hash) {
		t.Error("Expected invalid pending state to be cleaned up")
	}
}

// TestTickNotReadyYet tests tick with requests not ready to fetch
func TestTickNotReadyYet(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	block := createTestBlock(101)
	announce := &blockAnnounce{
		origin: "test-peer",
		hash:   block.Hash(),
		number: block.NumberU64(),
		time:   time.Now().Add(time.Hour), // Not ready yet - future time
		fetchWitness: func(hash common.Hash, responseCh chan *eth.Response) (*eth.Request, error) {
			return nil, nil
		},
	}

	state := &witnessRequestState{
		op: &blockOrHeaderInject{
			origin: "test-peer",
			block:  block,
		},
		announce: announce,
		retries:  0,
	}

	manager.mu.Lock()
	manager.pending[block.Hash()] = state
	manager.mu.Unlock()

	// Test tick with not-ready request
	manager.tick()

	// Verify retry count didn't increase (request wasn't processed)
	manager.mu.Lock()
	retries := state.retries
	manager.mu.Unlock()

	if retries != 0 {
		t.Errorf("Expected retry count to remain 0 for not-ready request, got %d", retries)
	}
}

// TestSafeEnqueueSuccess tests successful enqueue with peer success reset
func TestSafeEnqueueSuccess(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	var enqueueRequests []*enqueueRequest
	var enqueueMutex sync.Mutex

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Start goroutine to collect enqueue requests
	go func() {
		for req := range enqueueCh {
			enqueueMutex.Lock()
			enqueueRequests = append(enqueueRequests, req)
			enqueueMutex.Unlock()
		}
	}()

	peer := "test-peer"

	block := createTestBlock(101)
	witness := createTestWitnessForBlock(block)
	op := &blockOrHeaderInject{
		origin:  peer,
		block:   block,
		witness: witness,
	}

	// Add to pending
	manager.mu.Lock()
	manager.pending[block.Hash()] = &witnessRequestState{op: op}
	manager.mu.Unlock()

	// Test successful safeEnqueue
	manager.safeEnqueue(op)

	time.Sleep(10 * time.Millisecond) // Give time for async processing

	// Verify block was enqueued
	enqueueMutex.Lock()
	reqCount := len(enqueueRequests)
	enqueueMutex.Unlock()

	if reqCount != 1 {
		t.Errorf("Expected 1 enqueue request, got %d", reqCount)
	}
}

// TestConcurrentWitnessFetchFailure tests that handleWitnessFetchFailureExt
// can be called concurrently without causing race conditions
func TestConcurrentWitnessFetchFailure(t *testing.T) {
	quit := make(chan struct{})
	defer close(quit)

	dropPeer := peerDropFn(func(id string) {})
	enqueueCh := make(chan *enqueueRequest, 10)
	getBlock := blockRetrievalFn(func(hash common.Hash) *types.Block { return nil })
	getHeader := HeaderRetrievalFn(func(hash common.Hash) *types.Header { return nil })
	chainHeight := chainHeightFn(func() uint64 { return 100 })

	manager := newWitnessManager(
		quit,
		dropPeer,
		enqueueCh,
		getBlock,
		getHeader,
		chainHeight,
	)

	// Start the manager
	manager.start()
	defer manager.stop()

	hash := common.HexToHash("0x123")
	peer := "test-peer"
	err := errors.New("fetch failed")

	// Run multiple concurrent calls to handleWitnessFetchFailureExt
	// This should not cause a race condition panic
	var wg sync.WaitGroup
	numGoroutines := 100

	for range numGoroutines {
		wg.Add(1)
		go func() {
			defer wg.Done()
			manager.handleWitnessFetchFailureExt(hash, peer, err, false)
		}()
	}

	wg.Wait()
}
